Electric welding-machine.



C. M. AGNEW.

ELECTRIC WELDING MACHINE.

APPLICATION FILED MAY4,1914.

66,648, Eatented 5311.4, 1916.

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ELECTRIC WELDING MACHINE.

APPLICATION FILED MAY 4, m4.

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ELECTRIC WELDING-MACHINE.

Specification of Letters Patent.

Patented Jan. 4, 1916.

Application filed May 4, 1914. Serial No. 836,070.

To all whom it may concern Be it known that I, CLAIR M. Aoxnw, a citizen of the United States, residing at Milwaukee. in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Electric \Yelding-Machines, of which the following is a specification, reference being had to the accompanying drawing. forming a part thereof.

This invention relates more particularly to butt-welding" machines. so-called, and its main objects are to facilitate the control or closing of the electric circuit by the operator: to automatically open the circuit when the proper weld has been eifected; to enable the operator to determine and regulate the degree of pressure applied to a weld; to prevent overheating the metal and waste of time and power; to readily predetermine the amount of upset of metal parts of any given cross section to produce proper welds; to produce better and more uniform welding; and generally to im rovethe construction and operation of machines of this class.

It consists in the construction, arrangement and combination of parts as hereinafter particularly described and pointed out in the claims. I

In the accompanying drawing like characters designate the same parts in the several figures.

Figure 1 is a view partially in front elevation and partially in vertical section on the line 11, Fig. 2, of a machine embodying the invention; Fig. 2 is a vertical section on the line 22. Fig. 1: Fig. dis a. plan view of the machine; Fig. '1 is a side elevation of the circuit closing. locking and releasing device as viewed from the right relative to Fig. 3; Fig. 5 is a plan view of a modification of the clamp operating lever and circuit controlling devices connected therewith; and Fig. 6 is an enlarged cross section on the'line 66, Fig. 5.

Referring to Figs. 1, 2, 3 and 4, the machine comprises two clamping members mounted on slides 1 and 2, fitted and movable on transverse horizontal ways 3, on the top of a box frame 1. Each clamping member consists of a pair of jaws 5 and 6, the lower jaws 5 being detachably mounted upon and secured to the slides 1 and 2, and the upper jaws 6 being adjustably and detachably fastened to arms 7, which are pivoted at their rear ends" to standards 8, on

said slides. The jaws 6 are moved upwardly from the relatively stationary jaws 5, and are normally held separated therefrom by springs 9 interposed between said slides and the arms '7. I

The relatively stationary clamping menr ber which is mounted on the slide 1, is held 111 place against the pressure exerted upon the pieces to be welded by an adjustable stop 10. The slide 9. of the movable clamping member is connected by a link 11 with a hand lever 1:2, which is fulcrumed at 13 on the top of the frame 1 at one side thereof. An adjustable stop 11, limits the movement of the slide 2 away from the slide 1, and determines the degree of separation of the clamping members by the lever 12.

The vertically movable jaws 6 of the clamping members are forced against the tension of the springs 9 toward the jaws 5,

and the parts to be welded are clamped and held between said jaws by treadles or footlevers 15, which are fulcrumed in the base or lower part of the frame 1, and are connected at their rear ends by rods 16 with rearwardly projecting arms of bell crank levers 17, which are fulcrumed at their elbows on thestandards 8 of the slides 1 and 2 respectively the joints between the rods 16 and levers 15 and 17 are sufiiciently loose to permit the movement of the slide .2- by the lever 12, and the adjustment of the slide 1 without causing the operating connections of the jaws 6 to bind. The upwardly projecting arms of the levers 17 are adjustablv connected by rods 18 with the upper ends-of levers 19, which are fulcrumed on the standards 8, and are provided at their lower ends with rollers :20, engaging the upper sides of the arms 7.

lhe jaws 5. which serve also as electrodes for conducting currentto the parts to be welded, are connected by flexible conductors 21 with the secondarycoil or conductor 22 of a transformer. which is inclosed in the box frame 1.

The coil or conductor '22.

which is U-shaped. embraces the upper limb of an annular or four-'limbed laminated core 23. The transformer has two'primary coils or conductors '21, surrounding the upper limb of the core 23 on each side of the secondary coil or conductor 29, and these primary coils are connected. as shown in Figs. 1 and 3, by wires or conductors 95. with an electric generator or source of current (not shown),

and with normally separated contact pieces 26 and 27, which for convenience are called closing-contact pieces, and are mounted on the laterally extended shank of the clamp operating lever 12. T he contact piece 26 is removably fitted in or attached to a holder 23, which is guided in a bearing on the lever 12 and is movable toward and from the contact piece 27. The holder 28 is pivoted to one end of a transverse lever 29, which is fulcrnmed on the lever 12 and is connectedat its opposite end by a rod 30 with an angular hand grip 31, pivoted to the lever 12 adjacent to its handle. as shown in. Fig. 3. A spring 32, interposed between the lever 12 and the hand grip 31, tends to retract the contact piece 26 and hold it out of engagement with the contact piece 27. The contact piece 2? has a sliding bearing on the lever 12 and is yieldingly held projected toward the contact piece 26 by a spring 33, to insure good electrical contact between said contact pieces when they are brought together. A latch 31, pivoted to the outer side of the lever 12, is adapted by engagement with the lever 29, to hold the contact pieces 26 and 27 in engage1nent with each other when they are brought together. A spring 35, shown in Figs. 1 and *1, tends to hold the latch 31 in engagement with the lever 29. A magnet 36, whose plunger 37 is connected with the latch 31, operates when energized, to withdraw the latch against the tension of the spring 35 from engagement with the lever 29. The winding of magnet 36 is connected by wires 33 and 39 with contact pieces 10 and 11, which are mounted upon and insulated from the standards 8 of the clamping members, in axial alinement with each other. The wire or conductor 39 is formed into or connected with an auxiliary secondary coil 13 on the lower limb of the transformer core 23. The contact pieces 10 and 11 for convenience are called cut-out contact pieces. The contactpiece 10, made in the form of a screw which is threaded in an insulated block, is adjustable toward and from the contact piece 41, being locked in adjusted position by a nut which serves also to clamp and fasten the terminal of the wire 38 to the insulated block in which the screw is threaded. The opposing contact piece 11 with which the terminal of the wire 39 is connected between two clamping nuts, is fitted to slide in the insulated block mounted on the standard 8 of the slide 1, and is yieldingly held projected toward the contact piece 10 by a spring 12 interposed between said insulated block and a collar fastened on the contact piece, which is made in the form of a partially threaded bolt.

The latch .31 is formed or provided, as shown in Figs. 3 and 4. with a handle, by which it can be manually operated if desired, to release the lever 29 and permit the separation of the contact pieces 26 and 27 independently of the magnet 36. A detent 4A is pivoted on the lever 12 and adapted to be turned into position as indicated by dotted lines in Fig. 3, to hold the latch 31 out of engagement with the lever 29, so that the circuit may be opened as well as closed by the hand grip 31 at the will of the operator.

The lever connections for closing the jaws 5 and 6 of the clamping members are constructed and adjusted so that the axes of the rollers 20 will pass backward beyond a vertical plane intersecting the fnlcrums of the levers 19, and thus lock and hold the upper jaws 6 in closed position when the levers 15 are depressed.

To facilitate throwing the lower ends of the levers 19 forward and releasing the aws 6, the machine is provided with a treadle or foot lever 15 located between the levers 15 and having a cross piece 46 at its rear end adapted by engagement with the levers 15 on the under side thereof to lift their front ends when said lever t5 is depressed.

1n the operation of the machine, as here inbefore described, the jaws 6, the stops 10 and 1-1, and the cut-out contact pieces :10 and 41 having been properly adjusted for buttwelding metal parts of a given thickness or section, the parts to be welded are clamped between the jaws 5 and 6 by depressing the levers 15. The operator then grasping the hand grip 31 with the handle of the lever 12, moves the contact piece 26 into engagement with the contact piece 27,-thereby closing the circuitthrough the primary coils or conductors 21 of the transformer and inducing a welding current in the secondary coil or conductor 22 of the transformer, conductor 21, clamping jaws 5, and the parts to be welded, which are gripped and held between said jaws and the jaw 6, the clamping members and the parts held thereby being forced together by the operator pulling the lever 12 toward him. l-Vhen the primary circuit of the transformer is closed by means of the hand grip 31, the latch, 34 is forced upward by the spring 35 into engagement with the lever 29. thereby locking and holding the contact piece 26 in engagement with the contact piece 27. As soon as the parts to be welded, which are heated to a' welding temperature while they are subjected to pressure, have been'upset sufficiently to permit the contact piece 10 to be brought into engagement with the contact piece 41, the circuit including the magnet 36 and the coil 43, is closed, and the magnet being thus energized by the current induced in the coil 43, retracts the latch 31 and releases the lever 29. whereupon the contact piece 26 is separated from the contact piece 27 by the spring 32, thereby breaking the primary circuit of the transformer and cutting off the welding current while the parts at a welding temperature are still subjected to pressure.

In the adjustment of the cut-out piece 40' for welding parts of a given thickness or section, it is set at a distance from the contact piece 41 equal to about one-half the thickness of the parts to be welded when they are .held between t he aws of the clamping members in contact with each other. This pro- 'vides for the requisite upsetting of the metal toproduce a good weld when the parts to be welded are sufiiciently heated and forced together, and relieves the operator of the care and attention required to cut off the current at the proper time in making a weld) By depressing the lever 45 the front ends of the levers 15 are thrown upwardly and the lower ends of the levers 19 are swung forwardly, thereby releasing the jaws 6 and permitting them to be thrown upwardly by the springs 9. The work being thus released by the clamping jaws, the slide 2 with the jaws mounted thereon, is withdrawn by the lever 12 to its original position against the stop 14 for making another weld.

Under certain conditions it is sometimes well as to close the circuit manually, indecontact pieces 40 and 41. To accomplish I this the detent 44 is turned outwardly into further facilitate controlling the electriccurrent or closing the circuit, the clamp operating lever 12 is preferably provided, as shown in Figs. 5 and 6, with a pivoted handle 47, having a limited movement independent of said lever between opposing stops 48 and 49. A spring 59 interposed between the stop 49 and an adjusting screw 51, threaded in the shank of the handle transversely thereto, holds the handle normally in the position in which it is shown with its shank against the stop 48, the screw 51 being locked in adjusted position by a j a-Innut. A hook or dog 52, pivoted toan arm 53, projecting laterally from the handle shank, is

held by a spring 54normally in engagement with the head on a rod 30,which is pivotally connected with the lever 29, and is guided by a bearing 56 on the lever 12. The vshank of the handle is provided with an adjustabletrip for disengaging the hook or dog 52 from the head 55, when the handle 47 is turned on its pivot to the left or to-" 3 ward the machine and the spring is comx operator.

desirable to enable the operator to open as pendently of the magnet 36 and the cut-out pressed to a certain extent. This trip consists, as shown, of a screw 57, threaded in the handle shank transversely thereto and secured in adjusted position by a jam nut. With this construction of the clamp operating leverand circuitclosing mechanism, the latch 34, the cut-out contact pieces 40 and 41 and the magnet 36 may be omitted, but for certain kinds of work they are desirable, and

a the machine is preferably supplied with such parts so that the same amount or degree of upset in different welds may be obtained without care, or attention on the part of the For this reason the end of the rod 30, which is connected with the lever 29, is formed with a slot 58, and a retracting spring 59 is connected with said lever to permit the hook or dog 52 to release the rod 30 without releasing the lever 29 and permitting w the contact piece 26 to close the circuit when acertain degree of pressure is exerted on the lever handle 47 before the parts being welded have been upset \to the desired extent.

The rod 30 is also provided with a retracting spring 60 interposed between a collar thereon and the bearing 56 so as to return the rod to its initial position before the lever 29 is released by the latch 34 to permit the spring 59 towithdraw' the contact piece 26 from engagement with the contact piece 27.

To enable the operator to determine approximately the pressure exerted bythe lever 12 on a weld and by comparison to subject successive welds of'like articles to corresponding pressures, theshank of the handle 47 is provided with an index or pointer '61 and the adjacent face of the lever is provided with a scale.

In the operation of the machine with the hand lever 12 and circuit controlling devices constructed as shown in Figs. 5 and 6 without using the latch 34, the tensionzfof the spring 50 and the trip screw 57 having been adjusted to release the contact piece 26 wvhen a certain pressure is exerted on the weld, the initial movement of the handle 47 to the left compresses the spring 50, applies more or less pressure to the work according to the adjustment of said spring, and thrusts the contact piece 26 into engagement with the contact piece 27, thereby closing the circuit through the primary windings 24 of the transformer and inducing a current through the secondary conductor 22 and parts to be welded. After the circuit is closed thepressure may be gradually or rapidly increased or varied at will, but when it isincreased to a certain degree, depending upon the adjustment of the spring 50 and the trip screw 57, the hook or dog 52 is thrust by the trip screw outof engagement with the head 55 of rod 30, thereby releasing the lever 29 and iio permittingthe springs 59 and 60, or either,

of them in case but one is used, to withdraw the contact piece 26 from engagement with the contact piece 27 and thus break the circuit. When the handle 47 is released by the operator, the spring 50 returns it to its initial position relative to the lever 12 and carries the hook or dog 52 into engagement with the head 55, so that the circuit may be closed through and pressure applied again to the same weld if desired, or another weld may be made. The yielding contact piece 27 permits furthenmovement of the contact piece 26 and of the handle 47 relative to the lever 1 2 after the circuit is closed, in order to increase the pressure on the weld by further compression of the spring 50..

In connection with the latch 34, magnet 36 and cut-out contact pieces and 41 for automatically breaking the primary circuit of the transformer when a certain amount of upset of the parts being welded has been efl'ected according to the adjustment of the contact piece 40, irrespective of the pressure y the weld and to disengage the hook or dog 52 shortly before the contact pieces 40 and 41 would ordinarily be brought together, the

initial movement of the handle 47 tothe left againstthe resistance of the contacting 1 parts to be welded, compresses the spring 50,

and through the connection 'of'said handle with the lever 29 closes the primary circuit of the transformer. The latch 34:engaging withvthe lever 29, prevents the separation of the contact pieces 26 and 27, until the latch is withdrawn by the magnet 36. The

operator now-controls the pressure exerted through the lever 12, increasing. or varying it at will, such pressure being approximately indicated by the pointer 61 on 'the'scale, until p the trip screw thrusts the hook or dog 52 out of engagement with the head 55. The rod 30 being thus released, is thrust by the spring back to its initial position without effect on the lever 29 because of its slotted connection therewith. The pull of the operator o'n'the lever 12' coil 43', and the magnet being thus energized, retracts the latch and permitting the spring 59 to- Withdraw the contact'piece 26 from the contact piece 1 27 and open the primary circuit of the transformer, while the weld is'subjected to pressure. Thus the preliminary pressure to which the weld is subjected after the circuit is closed, is determinable and variable by the operator below a certain maximum limit dependent upon the adjustment of the spring 50 and of the trip screw 57, and, after that being continued, as soon as the contact piece 40 is brought into ena gagement with the'contact piece 41, the'cir- 1 cuit is closed through the magnet 36 and 34, releasing the lever 29 limit is reached the circuit is broken automatically when the weld has been upset to such an extent as will permit the contact piece 40 to engage the contact piece 41.

the invention asdefinedin the following claims. I

I claim:

1. In an electric welding machine the combination of clamping-members, one of which is movable toward and from the other, provided with insulated cut-out contact pieces one of which is adjustable relative to the member on which it is mounted toward and from the other, a source of current connected with the clamping members and with said contact pieces, a lever connected with the movable' clamping, member for applying pressure to a weld, circuit controlling mechanism comprising normallyjse parated closing contact pieces one of'which is movable and has an operating connection with said lever, a spring actuated latch for holding said closing contact pieces in engagement with each other, and a'magnet in circuit with the cut-out contact pieces adapted when said contact pieces, are brought together to retract said latch and break the circuit.

2. ln an electric welding machine the combination with clamping members, one of WllICll is movable toward and from the other,

having electric circuit connections,'of a lever for applying pressure to a weld connected with themovablemember'and provided with a pivoted handle and with stops for limiting the independent movement of the handle, circuit controlling mechanism comprising contact pieces one of which is movable toward and from the other, a lever connected with the movable contact piece, a spring tending to retract the movable contact piece and to breakthe circuit, a rod connected with the contactlever and guided on theclamping lever, a dog connected with the pivoted lever handle and adapted by engagement with said rod to close the circuit during the initial advance movement of the handle, a spring tending to hold the handle in its initial position, and a trip on thehandle adapted to disengage the dog from said rod and release the movable contact piece at a predeternnned point in the independent advance movement of the handle. I

"3. In an electric Welding machine the combination with clamping members, one of which is movable toward and from'the other, having electric circuit connections, of a lever for operating the movable member and applying pressure to a weld and provided with a pivoted handle and with stops for limlting the independent movement of the handle, circuit controlling mechanism comprising contact pieces one of which is movable toward and from the other, a lever connected with the movable contact piece, a. spring 1 tending to retract the movable contact piece and to break the circuit, a rod guided on the clamping lever and connected with the contact lever, a dog connected with the pivoted lever vhandle and adapted by engagement with said rod to close the circuit during the movable contact piece when the handle is i initial advance movement of the handle, an

adjustable spring tending to hold the handle in its initial position. and offering variableresistance to its advance movement, and an adjustable trip on the handle adapted to disengage the dog from said rod and release the member and applying pressure to a weld,

provided with a pivoted handle and with stops for limiting the independent movement of the handle, circuit closing contact pieces, one of which is movable toward and from the other, a lever connected with the movable contact piece, a spring tending .to

retract the movable contact piece and to,

break the circuit, a'rod guided on the clamping lever and having a slotted connection with the contact lever, a spring tending to retract saidrodto its initial position, a dog connected with the pivoted handle and adapted'by engagement with said rod to close the circuit, a spring tending to hold the handle in its initial position, a trip on the handle adapted to disengage the dog from said' rod at a predetermined point in the independent advance movement of the handle, an automatic latch for holding the movable closing contact piece in engagement with the other contact piece, cut out contact pieces mounted on the clamping members, and a magnet in circuit with the cut-out contact pieces and adapted when they are brought together to retract said latch and release the movable closing contact piece.

5. In an electric welding machine the combination with clamping members, one of which is movable toward and from the other, having electric circuit connections, of a lever connected with the movable member for applying pressure toaweld and providedwith a pivoted handle capable of limited movement independently thereof,

contact pieces one of which is movable toward and from the other, mounted on said lever, one of said contact pieces being yieldingly mounted, a lever fulcrumed on the clamping lever transversely thereto and connected with the movable contact piece, a rod connected with the contact lever and guided on theclamping lever, 21 dog connected with thepivoted lever handle and adapted by engagement with said rod to close the circuit during the initial advance movement of the handle, a spring tending to hold the pivoted handle'in its initial position and resistingrits advance movement relative to the clamping lever, and a trip adapted to disengage thedog from said rod and to release the movable contact piece when the handle is turned to a predetermined extent relative to the clamping lever.

6. In an electric welding machine the combination with clamping members having electric circuit connections, one of said members being movable toward and from the other, of a lever connected with the movable member for applying pressure to a weld and provided with a pivoted handle capable of a limited'movement independently thereof, circuit closing contact pieces, one of which is movable toward and from the other, mounted on said lever, a lever fulcrumed on the clamping lever transversely thereto and connectedwith the movable contact piece, a spring tending to retract the movable contact piece and to break the circuit, a rod guided on the'clamping lever and having a slotted connection with the contact lever, a spring tending to retract said rod to its initial position, a dogtconnected with the pivoted lever handle and adapted by engagement with said rod during the initial movement of thefhandle independently of the clamping lever to close the circuit, a spring tending to hold the pivoted handle in its initial position and resisting its advance movement independently of the clamping lever, a trip on the pivoted handle adapted to disengage the dog from said rod when the handle is subjected to a predetermined pressure, a latch on the clamping lever adapted to automatically lock the contact lever in position to close the, circuit, cut-out contact pieces mountedon tlie clampingmeinbers, and a magnet in circuit with said cut-out contact pieces, adapted when they are brought tocombination with clamping members having electric circuit connections, one of said I members being movable toward and from the ,other, of a lever connected with the movable member for applying pressure to a weld, circuit controllingcontact pieces,

one of which is movable toward and from the other, mounted on said lever, a lever fulcrumed 'on said *clamping lever transversely thereto and connected w th said movable contact piece, an operating rod conj necting the contact lever with the handle 7 of the clamping lever, a spring tending to retract the movable contact piece and 110 break the circuit, a spring lat ch pivoted on the clamping lever and adapted to autoi matically lock the movable contact piece in I -are brought together, to retract said latch and release the movable closing contact 10 piece. In Witness whereof Ihereto ai'fix my signature in presence of two witnesses.

, CLAIR M. AGNEW. Witnesses:

CHAs. L'Goss, FRED PALM. Y 

